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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Research Project #428968

Research Project: Absorption of mixed diets containing conventional, zinc-biofortified, or zinc added Bangladeshi rice among young peri-urban children.

Location: Obesity and Metabolism Research

Project Number: 2032-51000-005-01-T
Project Type: Trust Fund Cooperative Agreement

Start Date: Dec 1, 2015
End Date: Jun 30, 2019

Biofortification is becoming an increasingly promising population-based strategy for addressing zinc deficiency by enriching zinc in the edible portion of staple food crops by agricultural, agronomic, or genetic means. Zinc biofortified staple foods could lead to improved zinc intake, and thus reduced risk of dietary zinc deficiency, among those who currently have inadequate zinc intake, which includes approximately 55% of Bangladeshi children. This zinc absorption study will assess the feasibility of zinc biofortification programs for improving dietary zinc intake and thereby the zinc status and health of Bangladeshi children. The target for zinc biofortification has been set to provide an additional amount of bioavailable zinc in the food supply equivalent to about 40% of the physiological requirement of absorbed zinc for young children, and this zinc absorption study will provide crucial information about zinc absorption from a high zinc biofortified rice strain that is available in Bangladesh.

The objective of this randomized cross-over study in children aged 3-5 years is to determine zinc absorption from rice-based diets; comparing a zinc-biofortified rice with a conventional rice and a conventional rice + exogenous zinc fortificant. Our hypotheses are that children will absorb more zinc from the diet containing zinc-biofortified rice compared to the conventional rice diet, and the same amount of zinc from the conventional rice based diet with the exogenous zinc fortificant. The study will be conducted in the clinical research facilities of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b). Zinc absorption will be measured from rice-containing mixed diets, to allow for two separate sets of comparisons in two different groups of children. In comparison group A, a zinc biofortified rice-based mixed diet will be compared with a conventional rice-based mixed diet; and in comparison group B, the zinc biofortified rice-based mixed diet will be compared with a conventional rice-based mixed diet plus exogenous zinc fortificant. The total number of children in the study will be 48, with 24 in each group. Zinc absorption will be determined using a validated triple stable isotope tracer ratio method using 3 stable isotope tracers of zinc. All clinical work will be conducted at the icddr,b, and the WHNRC will be responsible for consulting with the investigators at the icddr,b on all aspects of the study. The WHNRC will provide clinical and laboratory supplies for administering the zinc absorption protocol, collecting biological specimens for health status, zinc status, and zinc absorption. The WHNRC will also be responsible for the zinc analyses necessary to determine zinc absorption.